Method of manufacturing black ash



Patented Aug. 6, 1929. I 1,723,138

UNITED" STATES PATENT OFFICE.-

ZOLTAN DE HOBVATH, OF RIVERSIDE, ILLINOIS, ASSIGNOR TO THE EAGLE PICHEB. LEAD COMPANY, OF GINCINNATI, OHIO, A CORPORATION OF OHIO.

METHOD OF MANUFACTURING BLACK ASH.

1 Drawing. Application filed Jctober'12, 1926. Serial No. 141,233.

My invention relates to the manufacture of rotary kiln a substantial percentage of carblack ash the commercial name of the subbonate of calcium and in the use of such a 4 stance produced by heating a mixture of bamixture in a rotary kiln. 1 rytes and carbonaceous material to a tempera- F or ordinary commercial barytes which 6 tare at which the barium sulphate is reduced contains on average about 4.80% silica I find to barium sulphide. This reduction is now that the mixture should be in the proportion quite commonly carried out in a rotary kiln of 2000 lbs. barytes 600 lbs. coal and 200 lbs. 50 through which the mixture is passed. limestone but more limestone or its equiva- It is recognized that in the described methlent should be used if the percentage of silica od some of the barium sulphate is not reduced greater.

to soluble barium sulphide but forms insolu- The addition of limestone or its equivalent ble compounds of barium which cannot be to the mixture under treatment notably in- 65 leached out from the black ash and I have creases the temperature of fusion of the black discovered that this is notably true where the ash formed and prevents the formation f 15 b te contains a high ercentage of silica rings in the kiln and while this is clearlyvdue which forms an insolu le barium silicate in large part to the prevention of the for-ma BaSiO at the temperature to which the mixtion of barium silicate it is also no doubt part- 60 ture is raised. .ly due to the fact that the presence of the lime lVhere the reduction of the barytes is eliectin the black ash in itself increases its temed in a rotary kiln much trouble has been perature of fusion and I therefore find it admet with owing to ring formation in the kiln vantageous to use lime even where little or which tends to clog it by diminishing its diamno silica exists in the barytes. e5 veter. Having now described my invention, what These ring formations are due to the mix- I claim as new and desire to secure by Letters ture under treatment becoming pasty or part- 'Patent is v ly fused at the ten'iperature at which black 1. In the method of manufacturing black ash is formed and I have discovered that this ash from barytcs in which a mixture of ba- 70 tendency to fusion of the black ash is largely rytes and carbonaceous material is passed due to the formation in it of compounds of through and heated in a rotary kiln the im- I barium sulphate and silica. provement which consists in adding to the The object of my invention is to increase said mixture carbonate of calcium in quantity the quantity of barium sulphide in-the black sufiicient. to raise the temperature of fusion 75 ash and particularly to prevent the formation of the mass.

of rings in the rotary kiln both of which ob- 2. In the method of manufacturing black jectsI have discovered can be attained by addash from barytes in which a mixture of baing to the mixture under treatment asubstanrytes and carbonaceous material is passed tial percentage of calcium carbonate which through and heated in a rotary kiln the im- 0 will combine with the silica present in the provement which consists in adding to the barytcs and prevent it from combining with said mixture carbonate of calcium in quanthe barium sulphate and my invention contity suificient to combine with a substantial sists, generally speaking, in mixing with the quantity of the silica present in the barytes. barytes and carbonaceous material previous to heating it to reducing temperature in a ZOLTAN on HORVATH. 

